Search Results

You are looking at 1 - 10 of 38 items for :

  • "hemoglobin mass" x
  • Refine by Access: All Content x
Clear All
Restricted access

Bent R. Rønnestad, Joar Hansen, Thomas C. Bonne, and Carsten Lundby

/A Cyclist G (M) 21/181 70 1041 79 N/A 1005 69 N/A N/A N/A Abbreviations: Hb mass , hemoglobin mass; HS, heat session; F, female; M, male; N/A, not applicable; T rec , rectal temperature; VO 2 max, maximal oxygen uptake. Note: T rec achieved during heat training sessions, Hb mass , and body mass are

Restricted access

Ida A. Heikura, Louise M. Burke, Dan Bergland, Arja L.T. Uusitalo, Antti A. Mero, and Trent Stellingwerff

change in hemoglobin mass (Hbmass) is considered an objective and relatively easily measured outcome of altitude exposure within a standardized altitude training protocol, with a typical increase of 2% to 5% being reported following a block of altitude training. 3 – 7 However, the mechanisms associated

Restricted access

Mitsuo Neya, Taisuke Enoki, Nao Ohiwa, Takashi Kawahara, and Christopher J. Gore

Purpose:

To quantify the changes of hemoglobin mass (Hbmass) and maximum oxygen consumption (VO2max) after 22 days training at 1300–1800 m combined with nightly exposure to 3000-m simulated altitude. We hypothesized that with simulated 3000-m altitude, an adequate beneficial dose could be as little as 10 h/24 h.

Methods:

Fourteen male collegiate runners were equally divided into 2 groups: altitude (ALT) and control (CON). Both groups spent 22 days at 1300–1800 m. ALT spent 10 h/night for 21 nights in simulated altitude (3000 m), and CON stayed at 1300 m. VO2max and Hbmass were measured twice before and once after the intervention. Blood was collected for assessment of percent reticulocytes (%retics), serum erythropoietin (EPO), ferritin, and soluble transferrin receptor (sTfR) concentrations.

Results:

Compared with CON there was an almost certain increase in absolute VO2max (8.6%, 90% confidence interval 4.8–12.6%) and a likely increase in absolute Hbmass (3.5%; 0.9–6.2%) at postintervention. The %retics were at least very likely higher in ALT than in CON throughout the 21 nights, and sTfR was also very likely higher in the ALT group until day 17. EPO of ALT was likely higher than that of CON on days 1 and 5 at altitude, whereas serum ferritin was likely lower in ALT than CON for most of the intervention.

Conclusions:

Together the combination of the natural and simulated altitude was a sufficient total dose of hypoxia to increase both Hbmass and VO2max.

Restricted access

Avish P. Sharma, Philo U. Saunders, Laura A. Garvican-Lewis, Brad Clark, Marijke Welvaert, Christopher J. Gore, and Kevin G. Thompson

been proposed, based on the belief a hypoxia-induced increase in erythropoietin is the primary physiological pathway enhancing postaltitude sea-level performance. 3 Recent reviews of the literature suggest that hemoglobin mass (Hb mass ), a key measurable outcome of the erythropoietic cascade

Restricted access

Mathew W.H. Inness, François Billaut, and Robert J. Aughey

Purpose:

To determine the time course for physical-capacity adaptations to intermittent hypoxic training (IHT) in team-sport athletes and the time course for benefits remaining after IHT.

Methods:

A pre–post parallel-groups design was employed, with 21 Australian footballers assigned to IHT (n = 10) or control (CON; n = 11) matched for training load. IHT performed eleven 40-min bike sessions at 2500-m altitude over 4 wk. Yo-Yo Intermittent Recovery Test level 2 (Yo-Yo IR2) was performed before; after 3, 6, and 11 IHT sessions; and 30 and 44 d after IHT. Repeated time trials (2- and 1-km TTs, with 5 min rest) were performed before, after, and 3 wk after IHT. Hemoglobin mass (Hbmass) was measured in IHT before and after 3, 6, 9, and 11 sessions.

Results:

Baseline Yo-Yo IR2 was similar between groups. After 6 sessions, the change in Yo-Yo IR2 in IHT was very likely higher than CON (27% greater change, effect size 0.77, 90% confidence limits 0.20;1.33) and likely higher 1 d after IHT (23%, 0.68, 0.05;1.30). The IHT group’s change remained likely higher than CON 30 d after IHT (24%, 0.72, 0.12;1.33) but was not meaningfully different 44 d after (12%, 0.36, –0.24;0.97). The change in 2-km TT performance between groups was not different throughout. For 1-km TT, CON improved more after IHT, but IHT maintained performance better after 3 wk. Hbmass was higher after IHT (2.7%, 0.40, –0.40;1.19).

Conclusion:

Short-duration IHT increased Yo-Yo IR2 compared with training-load-matched controls in 2 wk. An additional 2 wk of IHT provided no further benefit. These changes remained until at least 30 d posttraining. IHT also protected improvement in 1-km TT.

Restricted access

Blake D. McLean, David Buttifant, Christopher J. Gore, Kevin White, Carsten Liess, and Justin Kemp

Purpose:

Little research has been done on the physiological and performance effects of altitude training on team-sport athletes. Therefore, this study examined changes in 2000-m time-trial running performance (TT), hemoglobin mass (Hbmass), and intramuscular carnosine content of elite Australian Football (AF) players after a preseason altitude camp.

Methods:

Thirty elite AF players completed 19 days of living and training at either moderate altitude (~2130 m; ALT, n = 21) or sea level (CON, n = 9). TT performance and Hbmass were assessed preintervention (PRE) and postintervention (POST1) in both groups and at 4 wk after returning to sea level (POST2) in ALT only.

Results:

Improvement in TT performance after altitude was likely 1.5% (± 4.8–90%CL) greater in ALT than in CON, with an individual responsiveness of 0.8%. Improvements in TT were maintained at POST2 in ALT. Hbmass after altitude was very likely increased in ALT compared with CON (2.8% ± 3.5%), with an individual responsiveness of 1.3%. Hbmass returned to baseline at POST2. Intramuscular carnosine did not change in either gastrocnemius or soleus from PRE to POST1.

Conclusions:

A preseason altitude camp improved TT performance and Hbmass in elite AF players to a magnitude similar to that demonstrated by elite endurance athletes undertaking altitude training. The individual responsiveness of both TT and Hbmass was approximately half the group mean effect, indicating that most players gained benefit. The maintenance of running performance for 4 wk, despite Hbmass returning to baseline, suggests that altitude training is a valuable preparation for AF players leading into the competitive season.

Restricted access

Philo U. Saunders, Christoph Ahlgrim, Brent Vallance, Daniel J. Green, Eileen Y. Robertson, Sally A. Clark, Yorck O. Schumacher, and Christopher J. Gore

Purpose:

To quantify physiological and performance effects of hypoxic exposure, a training camp, the placebo effect, and a combination of these factors.

Methods:

Elite Australian and International race walkers (n = 17) were recruited, including men and women. Three groups were assigned: 1) Live High:Train Low (LHTL, n = 6) of 14 h/d at 3000 m simulated altitude; 2) Placebo (n = 6) of 14 h/d of normoxic exposure (600 m); and 3) Nocebo (n = 5) living in normoxia. All groups undertook similar training during the intervention. Physiological and performance measures included 10-min maximal treadmill distance, peak oxygen uptake (VO2peak), walking economy, and hemoglobin mass (Hbmass).

Results:

Blinding failed, so the Placebo group was a second control group aware of the treatment. All three groups improved treadmill performance by approx. 4%. Compared with Placebo, LHTL increased Hbmass by 8.6% (90% CI: 3.5 to 14.0%; P = .01, very likely), VO2peak by 2.7% (-2.2 to 7.9%; P = .34, possibly), but had no additional improvement in treadmill distance (-0.8%, -4.6 to 3.8%; P = .75, unlikely) or economy (-8.2%, -24.1 to 5.7%; P = .31, unlikely). Compared with Nocebo, LHTL increased Hbmass by 5.5% (2.5 to 8.7%; P = .01, very likely), VO2peak by 5.8% (2.3 to 9.4%; P = .02, very likely), but had no additional improvement in treadmill distance (0.3%, -1.9 to 2.5%; P = .75, possibly) and had a decrease in walking economy (-16.5%, -30.5 to 3.9%; P = .04, very likely).

Conclusion:

Overall, 3-wk LHTL simulated altitude training for 14 h/d increased Hbmass and VO2peak, but the improvement in treadmill performance was not greater than the training camp effect.

Full access

Rachel McCormick, Brian Dawson, Marc Sim, Leanne Lester, Carmel Goodman, and Peter Peeling

acted as their own control via comparisons in sFer response with baseline. Figure 1 —Diagrammatic representation of experimental overview. Note . sFer = serum ferritin; GXT = graded exercise test; Hb mass  = hemoglobin mass. *PATCH group only. During the supplementation period, the PILL group were

Restricted access

Erin L. McCleave, Katie M. Slattery, Rob Duffield, Stephen Crowcroft, Chris R. Abbiss, Lee K. Wallace, and Aaron J. Coutts

weeks of “Live High, Train Low” hypoxia (>10 h·d −1 ) combined with heat training. 14 – 17 Despite the reports of accelerated and long-lasting PV 15 and hemoglobin mass (Hb mass ) responses, 15 , 16 changes in physical performance following combined heat and “Live High, Train Low” have been

Restricted access

Rachel McCormick, Alex Dreyer, Brian Dawson, Marc Sim, Leanne Lester, Carmel Goodman, and Peter Peeling

, when iron requirements may be increased ( Hall et al., 2019 ). Hall et al.’s ( 2019 ) research established a greater hemoglobin mass (Hb mass ) response in athletes following single nightly doses of oral iron (200-mg elemental iron) as compared with that of a split daily dose (2 × 100-mg elemental iron